Police have apologised to women who came forward to say they were victims of a grooming gang after errors in the way evidence was handled led to criminal trials collapsing.

Northumbria Police launched Operation Optic after it received reports that three women had been the victim of child sexual exploitation about 10 years ago.

A series of trials were due to be held at Newcastle Crown Court involving men living on Tyneside who faced serious charges including rape, trafficking within the UK and grooming.

But significant problems regarding the way was secured repeatedly arose in the first trial, leading to its collapse this week, and the Crown Prosecution Service deciding any subsequent trials should not go ahead.

The defendants were cleared of all charges.

Reporting restrictions on the media were in put in place during the first trial.

Chief Superintendent Scott Hall, head of the force’s Safeguarding Department, praised the women for coming forward.

He said: “We have visited each to apologise for police failings which resulted in the cases not going ahead at court.

“These centred around how some evidence had been secured without meeting strict guidelines governing investigations.

“We will now conduct a review to understand how the failings occurred and it would therefore be inappropriate to comment any further at this stage.”

A CPS spokesman said: “During the course of this trial, it emerged that some of the evidence in these cases had not been secured in accordance with the strict guidelines governing police investigations.

“Given the significance of the issues that came to light, there was no longer a realistic prospect of securing a conviction in each case and the Crown took the appropriate decision to formally offer no evidence against the defendants.”